Today, I will be writing about the mini project I made for the subject “Theory Of Machines”.
The Automatic Stamping Machine.
The basic purpose of the machine is to create a stamp on small objects such as small cartons and packages. The machine has been designed as a workstation where objects are fed continuously one after the other. The machine stamps on the object and then pushes it off the workstation.(Into a bucket, crate or another conveyor as required.)
The machine uses 3 basic mechanisms intertwined and timed to create an alternate stamping and pushing motion. This is accomplished by using the Beam Engine mechanism, the Crank and Slider mechanism and the Crankshaft mechanism. The entire machine works on just one input motion which is the rotation of the crankshaft by means of a handle.
The mechanism was designed using Autodesk Force-Effect-Motion. This is an awesome android app (Its Free on the Play Store!;-) ) which allows you to recreate the various mechanisms and linkages that you see in daily life. I designed the links using this app and adjusted the relative angle between the two mechanisms to obtain the alternate actuation of the two mechanisms. There is no definite method except trial and error to adjust this relative angle and i found that 90 degrees was perfect as it allowed the synchronization of the TDC and BDC of the beam engine link and the crank slider link. After this, I created the entire mechanism in Autodesk Inventor 2012 as an assembly to get an idea of how it would look like.
Once the design was ready, the mechanism was ready to be built. The mechanism was made out of wood and assembled using various fasteners and adhesives. First, we made the links out of 10mm thick wooden blocks and drilled holes in them for attaching them later. The Vertical and Bottom plates were made out of 12mm thick plywood and they were attached using self tapping screws and 3 aluminum “L” brackets. The Crankshaft was made by cutting PVC pipes to size in 2 sections and attaching the mechanism links to it by 2 wooden links and a wooden pencil in between. The Handle was made by using a wooden block and attaching the holding end of an old stamp. The vertical and horizontal guide-ways were made from plywood along with the slots for the pusher rod. The pusher rod was made by attaching a small section of PVC pipe to the Sliding link. The stamp was made using a DIY stamp kit, reading “MECH ENG”. The stamp was attached to the end of the beam engine link.
Step 3-Assembly and Painting
The parts made individually had to be assembled so that the links could move freely in a constrained motion as per the design. This was attained by using rivets to attach the links. The sliding motion of the pusher arrangement was constrained by use of a long screw and held in position by washers and nuts. The pivot for the oscillating link was a screw held in position on the vertical plate by nuts on either side. The entire assembly was assembled on the crankshaft, after which the handle was attached on the opposite side of the vertical plate. Once assembled, the entire machine was painted by brush.
The project worked absolutely awesome. It took a lot of effort and hard work to make it and it really paid off! The feeding of objects can be added to the project by cutting an opening in the vertical plate or by adding a conveyor at an angle above the horizontal guide-way.The objects to be stamped will be fed by gravity automatically as the pusher moves back.
I would love to hear your thoughts on this project. Please reach out if you have anything to say!
Bye for Now!